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Subject: Re: [Intel PMC TGPIO Driver 1/5] drivers/ptp: Add Enhanced handling
 of reserve fields
To:     christopher.s.hall@intel.com, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, tglx@linutronix.de, hpa@zytor.com,
        mingo@redhat.com, x86@kernel.org, richardcochran@gmail.com,
        davem@davemloft.net, sean.v.kelley@intel.com
References: <20191211214852.26317-1-christopher.s.hall@intel.com>
 <20191211214852.26317-2-christopher.s.hall@intel.com>
From:   Jacob Keller <jacob.e.keller@intel.com>
Organization: Intel Corporation
Message-ID: <04485e14-52a0-3075-94d9-50d81f6b11da@intel.com>
Date:   Fri, 31 Jan 2020 09:02:13 -0800
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On 12/11/2019 1:48 PM, christopher.s.hall@intel.com wrote:
> From: Christopher Hall <christopher.s.hall@intel.com>
> 
> Add functions that parameterize checking and zeroing of reserve fields in
> ioctl arguments. Eliminates need to change this code when repurposing
> reserve fields.
> 

One thing to note that may be problematic with this handling: a later
usage of a reserved field must still be reported as zero for callers of
the old ioctl variants. Reserved fields were only handled properly in
the "2" variants of the ioctls.

This change might make it harder to notice and remember to ensure that
previously unused fields get zero'd for the old ioctls.

Richard, thoughts?

Thanks,
Jake